internal void Reset()
{
Codec.TotalBytesIn = Codec.TotalBytesOut = 0;
Codec.Message = null;
PendingCount = 0;
NextPending = 0;
_rfc1950BytesEmitted = false;
Status = WantRfc1950HeaderBytes ? InitState : BusyState;
Codec._Adler32 = Adler.Adler32(0, null, 0, 0);
LastFlush = (int)FlushType.None;
InitializeTreeData();
_InitializeLazyMatch();
}
internal int SetDictionary(byte[] dictionary)
{
var length = dictionary.Length;
var index = 0;
if (dictionary == null || Status != InitState)
{
throw new ZlibException("Stream error.");
}
Codec._Adler32 = Adler.Adler32(Codec._Adler32, dictionary, 0, dictionary.Length);
if (length < MinMatch)
{
return(ZlibConstants.ZOk);
}
if (length > WSize - MinLookahead)
{
length = WSize - MinLookahead;
index = dictionary.Length - length;
}
Array.Copy(dictionary, index, Window, 0, length);
Strstart = length;
BlockStart = length;
InsH = Window[0] & 0xff;
InsH = ((InsH << HashShift) ^ (Window[1] & 0xff)) & HashMask;
for (var n = 0; n <= length - MinMatch; n++)
{
InsH = ((InsH << HashShift) ^ (Window[n + (MinMatch - 1)] & 0xff)) & HashMask;
Prev[n & WMask] = Head[InsH];
Head[InsH] = (short)n;
}
return(ZlibConstants.ZOk);
}
internal int Read_buf(byte[] buf, int start, int size)
{
var len = AvailableBytesIn;
if (len > size)
{
len = size;
}
if (len == 0)
{
return(0);
}
AvailableBytesIn -= len;
if (Dstate.WantRfc1950HeaderBytes)
{
_Adler32 = Adler.Adler32(_Adler32, InputBuffer, NextIn, len);
}
Array.Copy(InputBuffer, NextIn, buf, start, len);
NextIn += len;
TotalBytesIn += len;
return(len);
}
internal int Deflate(FlushType flush)
{
if (Codec.OutputBuffer == null ||
Codec.InputBuffer == null && Codec.AvailableBytesIn != 0 ||
Status == FinishState && flush != FlushType.Finish)
{
Codec.Message = ErrorMessage[ZlibConstants.ZNeedDict - ZlibConstants.ZStreamError];
throw new ZlibException($"Something is fishy. [{Codec.Message}]");
}
if (Codec.AvailableBytesOut == 0)
{
Codec.Message = ErrorMessage[ZlibConstants.ZNeedDict - ZlibConstants.ZBufError];
throw new ZlibException("OutputBuffer is full (AvailableBytesOut == 0)");
}
var oldFlush = LastFlush;
LastFlush = (int)flush;
if (Status == InitState)
{
var header = (ZDeflated + ((WBits - 8) << 4)) << 8;
var levelFlags = (((int)CompressionLevel - 1) & 0xff) >> 1;
if (levelFlags > 3)
{
levelFlags = 3;
}
header |= levelFlags << 6;
if (Strstart != 0)
{
header |= PresetDict;
}
header += 31 - header % 31;
Status = BusyState;
unchecked
{
Pending[PendingCount++] = (byte)(header >> 8);
Pending[PendingCount++] = (byte)header;
}
if (Strstart != 0)
{
Pending[PendingCount++] = (byte)((Codec._Adler32 & 0xFF000000) >> 24);
Pending[PendingCount++] = (byte)((Codec._Adler32 & 0x00FF0000) >> 16);
Pending[PendingCount++] = (byte)((Codec._Adler32 & 0x0000FF00) >> 8);
Pending[PendingCount++] = (byte)(Codec._Adler32 & 0x000000FF);
}
Codec._Adler32 = Adler.Adler32(0, null, 0, 0);
}
if (PendingCount != 0)
{
Codec.Flush_pending();
if (Codec.AvailableBytesOut == 0)
{
LastFlush = -1;
return(ZlibConstants.ZOk);
}
}
else if (Codec.AvailableBytesIn == 0 &&
(int)flush <= oldFlush &&
flush != FlushType.Finish)
{
return(ZlibConstants.ZOk);
}
if (Status == FinishState && Codec.AvailableBytesIn != 0)
{
Codec.Message = ErrorMessage[ZlibConstants.ZNeedDict - ZlibConstants.ZBufError];
throw new ZlibException("status == FINISH_STATE && _codec.AvailableBytesIn != 0");
}
if (Codec.AvailableBytesIn != 0 || Lookahead != 0 || flush != FlushType.None && Status != FinishState)
{
var bstate = _deflateFunction(flush);
if (bstate == BlockState.FinishStarted || bstate == BlockState.FinishDone)
{
Status = FinishState;
}
switch (bstate)
{
case BlockState.NeedMore:
case BlockState.FinishStarted:
{
if (Codec.AvailableBytesOut == 0)
{
LastFlush = -1;
}
return(ZlibConstants.ZOk);
}
case BlockState.BlockDone:
{
if (flush == FlushType.Partial)
{
Tr_align();
}
else
{
Tr_stored_block(0, 0, false);
if (flush == FlushType.Full)
{
for (var i = 0; i < HashSize; i++)
{
Head[i] = 0;
}
}
}
Codec.Flush_pending();
if (Codec.AvailableBytesOut == 0)
{
LastFlush = -1;
return(ZlibConstants.ZOk);
}
break;
}
}
}
if (flush != FlushType.Finish)
{
return(ZlibConstants.ZOk);
}
if (!WantRfc1950HeaderBytes || _rfc1950BytesEmitted)
{
return(ZlibConstants.ZStreamEnd);
}
Pending[PendingCount++] = (byte)((Codec._Adler32 & 0xFF000000) >> 24);
Pending[PendingCount++] = (byte)((Codec._Adler32 & 0x00FF0000) >> 16);
Pending[PendingCount++] = (byte)((Codec._Adler32 & 0x0000FF00) >> 8);
Pending[PendingCount++] = (byte)(Codec._Adler32 & 0x000000FF);
Codec.Flush_pending();
_rfc1950BytesEmitted = true;
return(PendingCount != 0 ? ZlibConstants.ZOk : ZlibConstants.ZStreamEnd);
}